Iodine: A versatile reagent in carbohydrate chemistry II. Efficient chemospecific activation of thiomethylglycosides
作者:K.P. Ravindranathan Kartha、Mahmoud Aloui、Robert A. Field
DOI:10.1016/0040-4039(96)01029-5
日期:1996.7
Iodine has been found to be an efficient promoter in the alcoholysis of unprotected or fully benzylated methyl 1-thio-β-D-galactopyranoside. Stereoselective formation of 1,2-cis linkages in oligosaccharide synthesis using “armed” thiomethyl glycosides as glycosyl donors was also observed. Protecting groups such as acetate, benzoate, benzylidene, isopropylidene, trimethylsilylethyl etc are stable under
key step for the synthesis of sugar-containing molecules such as glycolipids. However, traditional carbohydrate chemistry is characterized by extensive use of protective groups, resulting in laborious manipulations and poor atom economy. Here, we present a protecting-group-free glycosylation strategy employing dibenzyloxy-1,3,5-triazin-2-yl glycosides (DBT-glycosides) as glycosyl donors. The DBT-glycosyl
Triflation/iodination of appropriately substituted D-galactose derivatives enables the preparation of 4-deaoxy-4-iodo-D-glucose without epimerisation.
The preparation and study of some novel glycosides of D-galactose
作者:Prabhakar A. Risbood、Lawrence A. Reed、Leon Goodman
DOI:10.1016/s0008-6215(00)85538-x
日期:1981.2
Abstract The tert -butyl- and the 2,2,2-trichloroethyl α- and β- D -galactopyranosides were prepared and both α- D -glycosides were selectively benzoylated to give the 2,3,6-tri- O -benzoyl- D -galactopyranosides. Cleaving of the glycosidic groups is described. The glycosides are useful intermediates for oligosaccharide synthesis where generation of a reducing sugar terminus under mild conditions is